Power cutter

Abstract

A power cutter which comprises a main body provided with a motor, a work-cutting portion including a circular cutting blade to be rotated by the motor and a safety cover covering both sides of an edge portion of the cutting blade so as to form a dust-discharging passageway, a fan attached to the safety cover for sucking and removing dust generated during cutting operations through the dust-discharging passage, a barrier wall attached to the safety cover so as to intercept the dust-discharging passageway, and a main dust-sucking port and a supplementary dust-sucking port disposed respectively in front of and behind the barrier wall as viewed in the rotational direction of the cutting blade.

What is claimed is: 
     
       1. A power cutter, comprising: a main body provided with a motor;   a work-cutting portion, including a circular cutting blade adapted to be rotated by said motor and a safety cover disposed over and covering both sides of an edge portion of said cutting blade so as to form, together with said cutting blade, a dust-discharging passageway within the safety cover, the safety cover including a peripheral wall portion and side wall portions;   a fan having a fan case with a bottomed cylindrical portion attached in an opening of said safety cover for sucking dust generated during a cutting operation using the circular cutting blade and removing the sucked dust from said dust-discharging passageway of the safety cover;   a barrier wall within the dust-discharging passageway and extending between the side wall portions and the peripheral wall portion of the safety cover so as to substantially block the dust-discharging passageway, the barrier wall having a slit for the cutting blade;   a main dust-sucking port formed in the bottomed cylindrical portion of the fan case and disposed in front of the barrier wall with respect to the rotational direction of the cutting blade, and   a supplementary dust-sucking port formed in the bottomed cylindrical portion of the fan case and disposed behind the barrier wall with respect to the rotational direction of the cutting blade for sucking dust from the dust-discharging passageway that leaks past the barrier wall through the slit.   
     
     
       2. The power cutter according to claim 1, wherein said barrier wall is constituted by an outer peripheral wall portion disposed along an outer periphery of said cutting edge portion and by a pair of extended wall portions disposed on both sides of said cutting edge portion, said pair of extended wall portions being separated by a slit-shaped opening having a predetermined width to allow said cutting blade to rotate without contact with said extended wall portions. 
     
     
       3. The power cutter according to claim 1, wherein said barrier wall is disposed at a portion of said dust-discharging passage where the cross-sectional area of said passage is approximately the largest. 
     
     
       4. The power cutter according to claim 3 wherein most of said main dust-sucking port and most of said supplementary dust-sucking port are located outside the outer periphery of the cutting edge of said cutting blade. 
     
     
       5. The power cutter according to claim 3 wherein both said main dust-sucking port and said supplementary dust-sucking port are non-circular in shape. 
     
     
       6. The power cutter according to claim 1 wherein most of said main dust-sucking port and most of said supplementary dust-sucking port are located outside the outer periphery of the cutting edge of said cutting blade. 
     
     
       7. The power cutter according to claim 6 wherein both said main dust-sucking port and said supplementary dust-sucking port are non-circular in shape.